Estrus
by Annenburg
Summary: Spock joins his mother on a trip to Earth to visit her old friend, Winona. While there, he meets Winona's daughter, Jamie, and the dominoes begin to fall as she slowly overwhelms all of him. A teenage AU. Eventual pregnancy involved.
1. Chapter 1

_The author in no way owns the Star Trek franchise or in any way has claim to the characters and entities that are part of it. All original plots, storylines, and characters contained within this work are, however, property of the author, Naelle Annenburg. Use of any of these is acceptable only if the author releases permission._

_This story contains: genderbending, sexual content, and adult language._

"_Estrus"_

_

* * *

_

The most intoxicating scent washes over Spock as he enters the small farmhouse, catching him unaware as he removes his shoes. He is frozen for a moment, bent precariously with one hand gripping the back of his shoe. The scent is vaguely familiar to him – perhaps something he encountered in childhood – but attempts to identify it fail one after another.

He is aware of his mother stepping out of her shoes beside him, and before she can realize his behavior, he works himself out of his own. He takes a moment longer than he requires to ensure that they are straight and not blocking the doorway, and then he straightens his back and glances to his mother.

If she had noticed his unusual behavior, she isn't letting on. Her eyes are fixed on a delicate-looking blonde woman, paler than her and propping visibly calloused hands on her ample hips. Both women smile, teeth flashing, and then his mother is moving forward to wrap her arms around the woman he assumes to be Winona-from-college.

"God, you look so _great!_" presumably Winona says, tones high and openly gleeful. Spock is reminded briefly of his mother's Terran music, of songs with lyrics that are _sung_, not chanted. He is out of place. Winona ignores him. "Are you tired? You must be tired. Come in; I'll make some tea!"

His mother nods, still smiling, and turns back to Spock. "Come on in," she encourages him, although it is unnecessary to invite him in to a home he's already entered. "I'll introduce you to Winona and Jamie. No need to worry – I told them about your diet before we came here. They can accommodate you fine."

Ah, yes. He had been hungry before they'd entered the house, and he had mentioned it to her. The scent has clouded all bodily needs, and he estimates his pulse has accelerated by at least four percent. How very unusual.

He follows his mother into the kitchen, and the scent only grows stronger as he gets closer. He scarcely notices Winona bustling about in the kitchen, muttering to herself. "I always forget where I put that goddamn steeper," he hears her say, but it means very little to him. There are other sounds coming from a door next to the refresher, and he allows himself to be ushered into a chair by his mother.

"Found it!" a younger, clearer voice calls, and he watches a young human female emerge, hands wrapped around a mesh ball. Winona lets out a victorious sound and takes it from her immediately, turning to the counter. The girl bounces on her heels momentarily, then her eyes light on Spock.

She is not completely unlike a Vulcan woman – she is slim, with slender hands and a long neck. Unlike most post-pubescent women on Vulcan, however, she has very little body fat. Her breasts are hardly defined, each no more than a wrinkle in her low-cut tank, and her rear may actually be smaller than Spock's. Her face is open, expressive – he recognizes a look of curiosity on her face for a long second before a grin takes over her face.

"So _you're_ Spock," she says. Spock bites back a comment that indeed, there are no other Vulcan individuals in the vicinity – her sense of the obvious is plain to see. She moves to stand in front of him, hands on her hips and posture imitating Winona's from earlier.

"I presume you must be _Jamie_," he returns instead. She lets out a laugh.

"Well, there aren't any other teenage girls around here," she says, and Spock balks. Humans are not telepathic – she couldn't have picked up on his thoughts. "You have a keen sense of the obvious, Mr. Grayson."

His mother turns to her abruptly. "Actually, Jamie, his last name isn't Grayson," she corrects, and the girl raises an eyebrow. "Spock is the only part of his name you're going to be able to say."

Jamie grins again. "Try me."

Spock is sorely tempted to do just that – to give her his full name and watch her lips fumble around the unfamiliar phonemes. Before he can do so, the scent washes over him again, stronger than before – almost intoxicating. And he realizes with a start that the scent is coming from the girl before him. With the realization comes a flood of physiological reactions – his hands clench, his pulse accelerates again, and his ears burn at the tips.

_Fascinating_.

"Perhaps another time," he manages to say, voice level. Mild, perhaps. Jamie frowns, but she doesn't contest it, instead throwing herself back into the chair next to his and stretching one bare calf over her thigh.

"So, you're going to be staying for a couple days," she says, clearly seeking conversation. Spock believes he is in control enough to interact with her, though he is uncertain what these physiological reactions will result in. He nods in confirmation. "Cool. You ever been on Earth before?"

"I have not," he responds. Jamie brings a hand up to play with her messy ponytail, and he is briefly transfixed by the inside of her delicate wrist. "My mother assures me that it is 'blasphemous' that I am half-human and have not visited her home world, and as such she arranged for us to stay on Earth for the duration of my father's duties on-planet."

Jamie nods back. "And since our moms went to college together, this was the logical place to stay?"

Spock feels his pulse stabilize. Good. "My mother wished to reconnect with Winona in-person," he explains. In the kitchen, Winona lets out a stream of profanity. Spock doesn't look at what she's done. "She also felt I would benefit from meeting a human my age."

Jamie lets out a snort, and it takes Spock a moment to realize she is expressing amusement. "Oh yeah, lots of benefits to being around me," she smirks. "I'm not a very stellar example of a good human girl."

His mother shakes her head. Winona finally approaches, placing four mugs of tea on the table. She hands Jamie a hypospray, and the teenager grimaces. She places it against her neck and injects herself anyway. When she catches Spock staring, she shrugs her shoulders.

"Allergic to everything you can imagine. And some things you can't," she says, tone final. Spock decides not to question. Winona seats herself across from her daughter and finally turns her attention to Spock.

"So you're Amanda's boy," she observes. Spock nods, wondering at the human proclivity to vocalize the obvious. "You've got her eyes. Nice to meet you, by the way. I'm Winona."

Spock inclines his head. "It is agreeable to make your acquaintance," he returns, accepting one of the mugs. The scent of the tea is unfamiliar to him, but the taste is acceptable. Next to him, Jamie is liberally spooning honey into her own mug, stirring with vigor.

Her scent baffles him. It seems to grow stronger every minute, to the point where he's certain even other humans must be capable of detecting it. Neither Winona nor his mother appears to be affected, and he knows that humans are not adept at hiding physiological reactions. He concludes that her scent must either only be detectable by males or by species with greater olfactory strength.

It makes very little sense.

"You know, Karen moved in down the road," Winona informs his mother. His mother's eyes widen, and he recognizes a look of surprise on her face. The blonde woman smiles widely, showing her pointed canines. "I don't suppose you'd want to go surprise her, would you?"

His mother smiles back, and Spock recalls that Karen-from-college often appeared in the stories she told of her time with Winona-from-college. He determines the aforementioned Karen must be the same individual. "First thing in the morning, maybe," she says. "She makes the best pancakes, if I remember. Might as well charm some out of her!"

"I like the sound of that," Winona agrees. She traces one finger over the rim of her mug, turning her attention to Jamie. "Maybe you can show Spock around the farm tomorrow. I know you're not sold on Karen yet."

Jamie nods, then tips her head back to swallow the last of her tea. Spock watches her throat work the liquid down.

This is going to be a long two months.

**

* * *

**

When he wakes the next morning, it is to the sound of the front door slamming shut and the open laughter of two human women. He makes it to the window in time to see his mother, arms linked with Winona, begin down the dirt road, throwing her head back with mirth. He cannot recall her ever expressing so much emotion on Vulcan, and wonders if this trip may prove more beneficial to her than him.

The thought is pushed from his mind as he takes a long breath and is nearly overwhelmed by the potency of Jamie's scent. For a moment, he believes she must be in the room, perhaps hidden and watching for his reaction, waiting for him to—to—

To what?

His muscles have tensed, he realizes, and his chest feels like it's being compressed. He cannot breathe enough of this scent. He hears the clattering of dishes downstairs and, with some degree of surprise, he hears Jamie curse. She is nowhere _near_ this room.

Her scent has become so much stronger.

Before he can help himself, he is making his way downstairs. His sleepwear clings to his skin, and he wants nothing more than to simply tear it off his body. As he makes it down the stairway and the kitchen comes into view, his mind clears slightly, and he freezes. Jamie continues bustling around the kitchen, unaware that he is there.

He wonders what it is he wants from her. His body seems to be in control of him, overtaking his mind – and he needs to think this through.

He hasn't even known her for more than a day, and yet the attachment – the _attraction_ - he feels towards her is powerful. He knows, though he cannot fathom how, that they are compatible. Already he feels closer to her than anyone he's ever known, and he has no doubt that were he to enter her mind, he would find acceptance – perhaps even a perfect match.

But for now, he doesn't need to enter her mind.

With a surge of adrenalin (and various other hormones he doesn't care to identify at this moment), he realizes exactly what he wants.

It is primal, certainly. But Vulcans were once controlled completely by their baser urges, and his blood is burning in its own right. Her scent has induced something in him that perhaps a full Vulcan would not experience, and he imagines it to be similar to Pon Farr. He is overwhelmed by the urge to touch her, claim her, _mate her_.

He needs to enter her _body_.

This is unacceptable. He cannot subject her to this, and he cannot give in to his base instincts so—

But he wouldn't _have_ these instincts if they didn't serve a logical purpose, correct?

No. His mind is grasping, and he realizes how distant his control is. He needs to reign himself back in. He eases himself into a sitting position on the stairwell, breathing deeply and attempting to ignore Jamie's overpowering scent. He needs to regain his control, and one way or another he is going to do so. He does not trust himself to make it back to his room without turning back to return to the young woman's vicinity.

He meditates lightly, aware that he will need to do so again and again over the course of his stay here. Slowly, his mind returns to him, though his blood still smolders in his veins. It will begin to burn again soon.

Perhaps he will need to distance himself from her.

When Spock completes this light meditation, he opens his eyes to find the source of this conflict staring directly at him. She is standing at the base of the stairs, her eyes precisely level with Spock's. One hand is on her hip; the other holds a tricorder.

"I heard you stop on the stairs and saw you go all green," she explains, neither hastily nor leisurely. Her head tilts to the side. "I thought you might be sick, so I grabbed this. The only problem is I have no idea what normal Vulcan readings are, let alone hybridized ones. So I'm just going to ask. Are you okay?"

He is not. Not one minute has passed since he finished meditating, and already he has returned to the state he had been beforehand.

"I am not ill," he says, reasoning that it isn't precisely a lie. Jamie moves up two steps, kneeling between his legs and reaching for his face. His mind blanks as she lays her hand on his forehead.

"I don't know. Even for a Vulcan, your temperature is pretty high," she says, and then she freezes. He feels it too – her confusion, attraction, concern, and the sudden, inexplicable urge that has gripped both of them. Her face colors pink, and he is transfixed by the exotic hue. And he knows that he isn't the only one fighting a base instinct.

With every bit of self-control he has, Spock reaches for her hand, carefully removing it from his forehead and standing. Her blue eyes are so wide, and for a moment his control sways. But he releases her, carefully clasping his hands behind his back as he mentally recites a desperate mantra to regain some measure of restraint. For a moment, the only movement is the gentle tremble of Jamie's shoulders as she watches him watch her, and he forces himself to take a step back.

He is achingly aroused.

"I need to attend to my studies," he says with haste, and it is not a lie. At some point in this vacation, he does need to return to his studies. He capitalizes upon the human proclivity to _assume_, however, and appropriately Jamie nods. He takes another step back. "I would appreciate privacy."

The girl nods again. "I can just head to Carol's for the day," she says, sounding nearly dazed. Spock ignores her tone. "Uh, have fun."

Spock inclines his head before turning on his heel and slowly walking back up the stairs. It is almost painful to remove himself from her presence, and in many ways he wishes to be beside her. However, with every breath, her scent robs him of that much more control, and he knows better than to trust his basest instincts in this instance.

He makes it to the room he's been assigned and shuts the door behind him. He simply cannot escape her scent, no matter what he tries. Removing himself from her physically is really his only choice.

Barely a minute passes before he hears the creak of the screen door, and from his window he watches her mount a bicycle and pedal down the road. An irrational part of him wishes to follow her, to snatch her from the seat and bring her back to this bed.

But he cannot.

Will not.

He arranges himself on the mattress and breathes, emptying his mind and resigning himself to a day of meditation.


	2. Chapter 2

_Warnings for this chapter: graphic sexual content._

Spock awakens to an empty house the next morning, and it is admittedly something of a relief. Jamie's scent still permeates the air, but it isn't so heavy and cloying as it had been before. Spock finds himself more than capable of concentrating on his studies, and he focuses as best he can on them.

He wonders again, briefly, at his mother's insistence that they stay with her old friend. While it is true that he has not seen her so emotional in years, the benefits to him remaining here elude him. He cannot be in Jamie's proximity without losing control, and her mother's presence only serves to distress him in a manner he cannot begin to explain. The other males of this house – Frank and Sam – are not present, and Spock is entirely isolated here.

But she wanted this. And he must respect that.

He has the house to himself for several hours, and he makes full use of his time. He considers calling his father, but with his mother absent he doesn't believe there will be much to discuss. Instead, he composes a few essays and reads a report on the Delphic Expanse while nursing a mug of tea in the kitchen.

It is almost unfortunate when the doors swing open again, and he finds himself unable to focus once again as the familiar, overpowering scent he's come to associate with Jamie Kirk wafts over him. It grows stronger every day, he thinks, and his control shatters at even the slightest exposure. He abruptly moves to wash his cup, and before he can even make it to the counter, the aforementioned blonde is bounding into the kitchen.

"Hey, Spock," she greets, and he manages a level response. He wonders if holding his breath would help. She strides past him, opening the cupboard and retrieving her own pack of tea. "Is the water still boiling?"

"Of course," Spock confirms, methodically rinsing his mug. He replaces it on the proper shelf as she searches out her own. Their hands nearly touch, and Spock recoils. He _cannot_ touch her again. The results would surely be disastrous.

Jamie's expression changes, and Spock all but senses danger. She stares at him for a moment, and he feels oddly like her prey as he watches her lips curve into a devious smirk.

Without warning, she jerks forward, hands reaching towards his face. Spock turns as quickly as he can, running with no particular thought other than _getting away_. He makes it to the stairs before she tackles him, and he begrudgingly concedes that her agility is particularly impressive, considering her species and build.

"Okay, enough!" she shouts as her arms clamp around his legs. He could escape, but at this point it makes no real difference. He knows she can catch him and that there is really nowhere to go. He meets her eyes and takes in her angry frown. "If I let you go, do you promise to be good?"

He nods, and she scrutinizes his face as if trying to decide whether to believe him. She apparently deemed him trustworthy, releasing him and crossing her arms. He turns so that he is seated on the stairs.

"So, you gonna tell me why you're treating me like you think I'm going to kill you?" she asks archly. Spock tries to ignore her scent. "Because seriously, I've been on my _best behavior_."

"I do not think you are going to kill me," he responds evenly. Jamie frowns again. "In fact, I believe you would be incapable of such an act. I have misjudged people before, though."

The human scoots forward, and he does his best to hold absolutely still. "You're so skittish. You're acting like an unbroken horse," she mutters. "You don't act this way with Mom. What makes it okay to treat me like this?"

He doesn't answer; he can't answer if he hopes to maintain any sense of dignity. He feels blood rush to his cheeks, unbidden, and knows that the flush must be obvious to Jamie. Sure enough, she blinks as she looks him over.

"See, you're all green again. Stubborn asshole," she mutters. Her hand moves to his cheek, and then both hands are cupping his face. Her breath stutters, and he knows that like yesterday, she is bearing witness to all the things she inspires in him. To the attraction and physical desire she makes him feel. He cannot move; if he does, he will surely die. It is too much already, feeling her sudden and intense desire flow through the points where their skin touches. It is only when she shifts her hips and that devastating scent washes over him again that he breaks.

His hands shoot out, shaking as he grips her waist and throws her onto his shoulder. She doesn't fight it – in fact, a bead of euphoria shoots through her skin and into him, and he knows that right now, he could do anything with her, anything at all, and she wouldn't object. A possessive thrill overtakes him at the very thought, and before he can help it he is carrying her back up the stairs, overcome with the need to do what he should've done when he saw her for the first time.

He forgoes the room he slept in the night before – 'Sam's' room – in favor of finding hers. It is not difficult – that intoxicating scent is almost as strong coming from the place she sleeps as it is coming from her. He slams the door behind them, nearly jogging to the bed in his haste. He throws her onto the blue bedding, peeling off his shirt before she's finished bouncing.

He is running on instinct here, and he supposes that will be enough. Jamie sends him an appraising glance, obviously appreciating his physique. His hands move to his pants, shoving them to the ground haphazardly, already fully erect.

Her eyes nearly glaze over when he moves forward, his erection twitching as he takes in her scent again. Jamie doesn't waste another second, yanking off her own shirt as Spock moves to pull her pants and undergarment down her legs, moving them to push his nose into the curls he finds under them.

Jamie lets out a noise he hasn't heard any Vulcan make, and he simply inhales her scent, nearly trembling at how it affects him. He doesn't believe he can become any more aroused without achieving orgasm, and yet he feels himself becoming almost imperceptibly harder. His phallus _aches_, and he knows he could change that very quickly if he simply entered her now.

He presses his mouth against her opening, finding it wet already. He will not need to assist with this, and he finds himself relieved. He moves up, pausing at her small breasts and mouthing over them. This brings her pleasure, he knows – he can feel it just as strongly as she does. He scrapes his teeth over one nipple and she trembles.

"Spock," she whines, and he looks up. Her pupils are dilated, mouth slightly open. He cannot help but freeze as he takes in her image. She swallows. "Spock, stop teasing. I need your fucking cock!"

Yes. Yes, she does. He agrees wholeheartedly, and without any further hesitation, he reaches down, lines himself up, and pushes into her, taking her in one smooth movement.

He feels her spasm around him, and he is shocked to feel a gentle orgasm flow from her. It cannot be finished already – he stills, watching her. But her climax subsides rather quickly, and she looks to him again, hands moving to his back.

"Are you gonna move or what?" she all but demands. Spock can't help anything anymore – he knows that, like he felt from her on the stairs, she could ask anything of him and he would be helpless but to do it. He starts a steady rhythm, bucking into her slowly and trying not to lose his mind. She is so soft, so tight, so slick – and she wants him so badly.

His control is lost after only a minute of this pace, and he finds himself pounding into her relentlessly. He barely pulls out before slamming back into base, and the loud slap of skin on skin, the slick sounds and the feel of her spasms and quivers and the pitch of her moans-he cannot imagine doing anything else for the rest of his life.

He doesn't know how long this goes on, but when he feels himself approaching orgasm, the knot in his cock beginning to swell, he reaches for her face, desperate to connect. He thinks she nods, and that is all the consent he requires, delving into her mind.

As he expected, he finds she complements him well. In their aroused states, the most superficial thoughts mostly involve some appreciation of his anatomy and endurance. There is some measure of desperation in her as well, and he knows it is related to her impending orgasm. Deeper still, there is a complex thought process at work, in some ways more impressive than a Vulcan's. And a thought pushes to the forefront of her mind as she works her way back through the meld and examines his mind:

_God, I want this for the rest of my life._

That single thought pushes him over the edge, his world splintering with the force of his climax. He feels hers shatter as well, pieces of her mixing with pieces of him, and when their worlds right themselves once more, he is shocked to find they have combined into a veritable mural, inextricably joined and bonded as a mating pair would be.

He pulls from her mind, unable to withdraw from her body both emotionally and physically. His knot has swollen, and it will have to recede before he attempts to leave her. She has no objection to this, chest heaving and arms still wrapped around his neck. He feels her exhilaration, and his heart manages to pound harder.

"Did you just marry me?" she asks. No, he thinks. He has simply bonded them. But for now, he nods, content to explain the difference later. She's quiet, and he feels her tinkering in their minds, examining this new construction. Then, abruptly, she sighs. "You know, most people _ask_ before they pull that kind of shit."

And he wonders how she can sound so angry when she _feels_ so pleased.


End file.
